1. Field of the Invention
This invention relates to pumps, and, more particularly, to liquid pumps of the rotary, positive displacement, and self priming pumps capable of being operated by hand or by the application of a source of rotary power such as a fuel-driven engine or an electrical motor.
2. Description of the Prior Art
The present pump is an improvement over a previously patented pump, U.S. Pat. No. 4,057,375 issued to Nachtrieb on Nov. 8, 1977 and which expired on Nov. 8, 1994.
In the prior art, positive displacement pumps and centrifugal pumps are used in moving fluids, typically liquids, from one location to another.
The centrifugal pump bases it pumping action by vortexually swirling the liquid to be pumped at relatively high speeds, and, thereafterwards, allowing the the liquid to pass through a ported chamber. Such pumps are noted for their simplicity and relatively long operational life expectancies. Nevertheless, a centrifugal pump is also noted for [it's] its pump inefficiency, has only a small lift capacity, and produces only moderate head pressure. As a result, centrifugal pumps are usually arranged in staggered, serial stages in order to produce the desired high head pressures. But, such multi-staged centrifugal pumps are expensive, relatively complex in design, and are usually less efficient than a single stage centrifugal pump.
The pump in Nachtrieb is also a rotary-type fluid pump. However, the prior art pump of Nachtrieb is limited to functioning as a semi-positive displacement, and is not self priming as is the present invention described hereinafterwards. Additionally, the instant invention is self-priming. Another major difference lies in the design of the vane structures. In the pump design of Nachtrieb, the vane structures are limited to using vanes which are rectangular in shape and are straight in the cross-sectional view thereof. In the improved pump disclosed herein, the key elements have been improved upon in that the vanes do not have flat faces, but are contoured instead, and the new and improved pump is self-priming. Additionally, the various fluid pressure relief sections carved out of the housing structure; namely, the inlet/outlet pressure release chambers, the side pressure release chambers, the center compression release channels, and the side compression release channels are modified to vary or improve pump performance which result in a semi-positive displacement pump which is not self-priming.